Abstract
Labeled (65Zn) adult plum curculio (PC), Conotrachelus nenuphar (Herbst), that migrated to adjacent woodlots in fall 1982 reinfested the orchard in spring 1983. Spring migration is thought to include both a mass migration in a preferred direction (the reverse of fall migration direction) and an exploratory component by which PC seek optimal feeding and oviposition sites. A northwestern tendency was observed among PC migrating in one orchard in spring. PC were most active between 12 May (before tight cluster) and 27 June (June drop), with the highest speed of dispersion (4.4 m per insect per day) at fruit set. After emergence and migration to host trees, PC were found on the ground under apple trees, individually and in groups of up to 14 with equal numbers of each sex. As the growing season progressed, PC moved from outside rows adjacent to woodlots toward the center of the orchard, possibly searching for food, oviposition sites, and trees offering sufficient protection from desiccation. PC were more abundant in the southeastern part of the orchard and on early cultivars of trees with dense foliage. Implications for control and future research are discussed.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
